LP gas is classified into imports from gas producing countries and domestic production including by-products from production processes of petroleum products. Import terminals where LP gas carried from gas producing countries by tankers is stored and petroleum refinery terminals are referred to as primary terminals. LP gas is loaded into domestic vessels or tank trucks at a primary terminal and shipped to secondary terminals that are transit stations for LP gas transportation which are located longshore or inland. Then, the LP gas carried to a secondary terminal is transported to LP gas filling stations in various locations (delivery bases), where gas cylinders are filled with the LP gas.
Gas cylinders filled at the respective delivery bases are delivered by a deliveryman to customer homes such as general households, collective housings, and business facilities. A gas cylinder (supply facility) and a customer may have a one-to-one relation or one gas cylinder used in a collective housing and a plurality of customer users may have therebetween a one-to-plural relation. A used gas cylinder in a customer home is exchanged for a filled gas cylinder and is collected at a delivery base. Each delivery base is associated with a fixed delivery area for which a deliveryman is responsible. Based on a delivery list, each deliveryman visits customer homes within the delivery area and delivers gas cylinders.
The delivery list is prepared by predicting the amount of LP gas remaining in the gas cylinder based on the past gas usage results of the respective customers, the meter indication input results of the gas meters of the customer homes (also may be called customers), and delivery records for example collected in the database to carry out a delivery due date adjustment (also may be called delivery prediction) to prevent a gas shortage in the gas cylinder. Delivery lists are individually prepared for the respective responsible deliverymen and are distributed to mobile terminals carried by the respective deliverymen. The delivery lists are distributed to the respective deliverymen for each delivery due date at a date one day prior to the delivery due date. This allows the respective deliverymen to check the delivery route in advance and to plan a delivery schedule.
As described above, since the delivery list is distributed at a date one day prior to the delivery due date, the delivery list for the delivery on the next day is prepared based on the delivery record at a predetermined time (e.g., 17:00) at a date one day prior to the delivery due date. Specifically, the scheduled delivery amount of the current day not yet delivered at the timing of the preparation of the delivery list is included in the delivery list as each deliveryman's undelivered task data. However, the delivery operation is actually continued even after the inclusion and may be continued until late at night. In this case, the delivery list will include each deliveryman's undelivered task data including data regarding already-delivered ones (which causes a discrepancy between the delivery list and the delivery record). Therefore, data including the discrepancy is extracted and is used to instruct the respective deliverymen about delivery addresses not requiring delivery on the delivery due date. This instruction is based on a completely-analog operation and is not carried out by using computer processing to delete delivery address data from the delivery list or by distributing a new delivery list. Even when the latest delivery list is distributed by computer processing, there may be a case where delivery schedules or delivery routes planned in advance by the deliverymen must be changed significantly. Furthermore, delivery addresses to which the delivery is already completed after 17:00 on the previous day do not always uniformly occur for the respective deliverymen. Specifically, if the respective deliverymen are notified of the delivery addresses not requiring the delivery on the delivery due date, the scheduled delivery count of gas cylinders for the deliverymen may not be notified based on the latest situation. In this case, the deliverymen may have to move or exchange the delivery addresses. This consequently prevents an effective use of the delivery list distributed on the previous day. On the other hand, the delivery due date is determined so as to prevent a gas shortage. Thus, delivery prior to the delivery due date has no problem.
The present invention has been made in view of the disadvantages as described above. It is an objective of the invention to prepare a delivery list for an LP gas delivery business based on a delivery due date which does not correspond to data for the next day but corresponds to data α days later (e.g., 2 days later) as a next day delivery amount.